Surface plate protecting device in CMP apparatus

ABSTRACT

Damage of a surface plate used in a CMP apparatus due to troubles generated in repair or replacement of the surface plate, operation of the CMP apparatus, etc. is prevented. In order to solve the problem, the present invention provides a surface plate protecting device in the CMP apparatus, which is a surface plate  2  used in the CMP apparatus, wherein a polishing pad  16  is replaceably bonded with the upper surface of a sheet  8,  and the lower surface of the sheet  8  is bonded with the upper surface of the surface plate  2  by an adhesive agent  9  having adhesive force larger than the adhesive force of the polishing pad  16,  so that damage or the like of the surface of the surface plate  2  generated due to troubles, etc. in polishing of a wafer can be blocked by the sheet  8.

FIELD OF THE INVENTION

The present invention relates to a surface plate protecting device in a CMP apparatus and particularly relates to a surface plate protecting device in a CMP apparatus capable of preventing damage or the like on the surface of a surface plate generated in a CMP operation or the like.

BACKGROUND OF THE INVENTION

Conventionally, surface plate protection devices in CMP apparatuses of this type have never been present. The technique of Japanese Patent Application Laid-Open (kokai) No. 2001-131500 is known as a technique closest to that. In the technique described in Japanese Patent Application Laid-Open (kokai) No. 2001-131500, a double-sided adhesive tape is wound around in the state in which a separator is attached to one side of the double-sided adhesive tape and a polishing cloth is attached to the other side, and the adhesive surfaces of the both sides of the double-sided tape are protected by the separator so that a polishing pad is not warped due to the repulsion force of the separator when it is to be attached to the surface plate; thus, it is configured so that the polishing cloth can be attached to a surface plate. As a matter of course, the separator is removed when the polishing cloth is to be attached to the surface plate.

The above described conventional example cannot prevent damage, dent, etc. on the upper surface of the surface plate generated in, for example, operation of the CMP apparatus.

A polishing pad is attached to a surface plate used in a CMP apparatus, and the polishing pad is a consumable product and has to be periodically replaced. Damage, dent, etc. is sometimes generated on the surface of the surface plate due to carelessness, etc. in the replacement operation of the polishing pad. Also, the surface of the surface plate is sometimes damaged due to a trouble such as projection of a wafer in wafer polishing. Meanwhile, there is close relation between the shape of the surface of the surface plate and the wafer polishing shape; and, when the surface of the surface plate is, for example, damaged, the polishing performance of the wafer is affected depending on the degree of the damage. Therefore, when the surface of the surface plate is damaged or dented, the surface plate has to be repaired or replaced by a new surface plate. However, the repairing operation in the state in which the surface plate is attached to the CMP apparatus is difficult. Also, since the weight of the surface plate is heavy, the replacement operation is also not easy and requires considerably long operation time, and the operation of the CMP apparatus has to be stopped for a corresponding period of time; thus, there are problems that the operation efficiency of the CMP apparatus is reduced and, in addition, the economic burden is increased due to the synergetic effects of high manufacturing cost of the surface plate per se and labor and time taken therefore.

Thus, technical problems to be solved for solving the problems are generated, and it is an object of the present invention to solve the problems.

SUMMARY OF THE INVENTION

This invention has been proposed for achieving the above described object, and a first aspect of the invention provides a surface plate protecting device in a CMP apparatus having a surface plate used in the CMP apparatus, wherein a sheet is bonded with an upper surface of the surface plate by an adhesive agent, a polishing pad is further replaceably bonded with the upper surface of the sheet, so that damage of the surface of the surface plate generated in replacement of the polishing pad, wafer polishing, or the like is protected by the sheet.

According to this configuration, the sheet is bonded with the upper surface of the surface plate, the polishing pad is bonded with the upper surface of the sheet, and a polishing operation of a wafer is executed by the CMP apparatus.

A second aspect of the present invention provides the surface plate protecting device in the CMP apparatus, wherein the adhesive force of the adhesive agent bonding the upper surface of the surface plate with the sheet is larger than the adhesive force of the polishing pad.

According to this configuration, in regular replacement of the polishing pad, the polishing pad can be independently peeled off from the sheet bonded with the upper surface of the surface plate, and a new polishing pad is bonded with the surface of the remaining sheet bonded with the upper surface of the surface plate so as to execute the polishing operation of the wafer by the CMP apparatus according to the first aspect.

A third aspect of the present invention provides the surface plate protecting device in the CMP apparatus, wherein a chemically resistant material such as a fluorine resin is selected as the sheet.

According to this configuration, since the sheet selects the chemically resistant material, it is not eroded by slurry, which is, for example, acidic or alkaline, during the polishing operation of the wafer.

A fourth aspect of the present invention provides the surface plate protecting device in the CMP apparatus, wherein a lower surface of the sheet is subjected to surface treatment that increases a friction coefficient, and the adhesive agent bonding the lower surface of the sheet with the upper surface of the surface plate uses an adhesive agent having adhesive force equal to or more than the adhesive force of the polishing pad.

According to this configuration, the friction coefficient of the lower surface of the sheet is increased, and the adhesive agent uses the adhesive force equal to or more than the adhesive force of the polishing pad; therefore, the adhesive force between the sheet and the upper surface of the surface plate is reliably increased. As a result, in regular replacement of the polishing pad, the polishing pad can be independently and reliably peeled off from the sheet bonded with the upper surface of the surface plate, a new polishing pad is bonded with the surface of the remaining sheet bonded with the upper surface of the surface plate, and the polishing operation of the wafer by the CMP apparatus according to the first aspect is executed.

A fifth aspect of the present invention provides a surface plate protecting device in a CMP apparatus having a surface plate used in the CMP apparatus, wherein a sheet protecting a surface of the surface plate is provided, both sides of the sheet are respectively coated by adhesive agents having different adhesive force, the adhesive agent of the lower surface side having the adhesive force larger than the adhesive force of the upper surface side, the lower surface of the sheet is bonded with the upper surface of the surface plate by the adhesive agent having the large adhesive force, and a polishing cloth is replaceably bonded with the upper surface of the sheet by the adhesive agent having the small adhesive force, so that damage of the surface of the surface plate generated in replacement of the polishing cloth, wafer polishing, or the like can be protected by the sheet.

According to this configuration, in regular replacement of the polishing cloth, the polishing cloth can be independently peeled off from the sheet bonded with the upper surface of the surface plate, a new polishing cloth is bonded with the surface of the remaining sheet bonded with the upper surface of the surface plate, and the polishing operation of the wafer by the CMP apparatus is executed.

A sixth aspect of the present invention provides the surface plate protecting device in the CMP apparatus, wherein the surface of the sheet in the surface plate side is coated in advance by an adhesive agent having adhesive force larger than the adhesive force of the polishing pad, the sheet is bonded with the upper surface of the surface plate, and the polishing pad is bonded with the upper surface of the sheet.

According to this configuration, the sheet is coated in advance by the adhesive agent having the adhesive force larger than the adhesive force of the polishing pad; therefore, the adhesive agent having the large adhesive force is bonded with the upper surface of the surface plate and the polishing pad is bonded with the other side so as to constitute the CMP apparatus of the first aspect and execute polishing operation.

A seventh aspect of the present invention provides the surface plate protecting device in the CMP apparatus, wherein an outer coating sheet for preventing adhesion with another material is bonded with the surface of the adhesive agent coating the sheet.

According to this configuration, the sheet is coated in advance by adhesive agents, etc. having different adhesive force, and each of the adhesive agents is protected by the outer coating sheet.

In the first aspect of the invention, the polishing operation of the wafer by the CMP apparatus is executed in the state in which the sheet is bonded with the upper surface of the surface plate and the polishing pad is bonded with the upper surface of the sheet. Therefore, even when the wafer projects out in the polishing operation and broken pieces of the broken wafer involve the polishing pad, etc., the upper surface of the surface plate is not damaged since the upper surface of the surface plate is protected by the sheet.

Also in replacement of the polishing pad, the polishing pad is once peeled off from the sheet bonded with the upper surface of the surface plate, and a new polishing pad is bonded again. Even when damage is to be erroneously generated on the surface of the surface plate in the ordinary replacement operation of the polishing pad, the damage is blocked by the sheet, the surface shape of the surface plate is maintained in an appropriate state, a long surface plate life can be expected, and use of the sheet can be kept as long as damage or dent is not generated thereon. Therefore, the wafer polishing operation by the CMP apparatus can be most efficiently executed, and a high-quality wafer can be expected to be obtained. Thus, repairing, replacement, etc. of the surface plate can be suppressed to a minimum level, and there is an economical advantage.

In the second aspect of the invention, in addition to the effects of the invention described in the first aspect, since the sheet is bonded with the upper surface of the surface plate having the large adhesive force, the polishing pad bonded with the upper surface of the sheet by the adhesive agent having the adhesive force smaller than the adhesive force of the above mentioned adhesive agent can be independently and readily peeled off from the upper surface of the sheet. Therefore, regular replacement operations of the polishing pad can be readily executed. As a matter of course, since the upper surface of the surface plate is protected by the sheet also during the replacement operation of the polishing pad, there is an advantage that damage, etc. is not generated on the upper surface of the surface plate.

In the third aspect of the invention, in addition to the effects of the invention described in the first or second aspect, since the sheet is formed by a material excellent in chemical resistant property, the sheet is not eroded by the slurry, which is, for example, acidic or alkaline, during the polishing operation of the wafer by the CMP apparatus, and there is an advantage that the upper surface of the surface plate is always protected so as to prevent damage of the upper surface of the surface plate.

In the fourth aspect of the present invention, in addition to the effects of the invention described in the first or third aspect, since the friction coefficient of the lower surface of the sheet is increased and the adhesive agent having the adhesive force equal to or more than the adhesive force of the polishing pad is used, the adhesive force between the sheet and the upper surface of the surface plate is reliably increased, and there is an advantage that, in regular replacement of the polishing pad, the polishing pad can be independently, readily, and reliably peeled off from the sheet bonded with the upper surface of the surface plate.

In the invention of the fifth aspect, the sheet is bonded with the upper surface of the surface plate by the adhesive agent having the large adhesive force, and the polishing cloth is bonded with the upper surface of the sheet by the adhesive agent having the adhesive force smaller than that of the above mentioned adhesive agent; therefore, the polishing cloth can be independently and readily peeled off from the upper surface of the sheet. Therefore, there is an advantage that the regular replacement operation of the polishing cloth can be readily executed.

In the invention of the sixth aspect, in addition to the effects of the invention described in the first, second, or third aspect, since the sheet is coated in advance by the adhesive agent having the large adhesive force, the sheet is bonded with the upper surface of the surface plate by using the adhesive agent having the large adhesive force, and the polishing pad is bonded with the upper surface of the sheet; as a result, there is an advantage that the regular replacement operation of the polishing pad becomes more convenient.

In the invention of the seventh aspect, in addition to the effects of the invention described in the fifth or sixth aspect, since the adhesive agents coating the sheet in advance are protected by the outer coating sheets until adhesion of the sheet with the upper surface of the surface plate or adhesion of the polishing cloth, there is an advantage that the adhesive force is reliably maintained without damaging the adhesive agents so as to execute the bonding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an outline of a CMP apparatus;

FIG. 2 is a partially-cut-away front view showing the state in which a sheet and a polishing pad are attached on a surface plate;

FIG. 3 is a partially-cut-away vertical cross section showing a main part of the present invention;

FIG. 4 is a partially-cut-away front view showing another embodiment of the sheet;

FIG. 5 is a partially-cut-away perspective view showing further another embodiment of the sheet;

FIG. 6 is a partially-cut-away front view of the sheet and the polishing pad; and

FIG. 7 is an explanatory drawing showing a replacement state of the sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An object of protecting an upper surface of a surface plate used in a CMP apparatus and preventing damage and the like generated, for example, during operation of the CMP apparatus is achieved by providing a surface plate protecting device in the CMP apparatus, wherein the surface plate is used for the CMP apparatus, a sheet is bonded to the upper surface of the surface plate by an adhesive agent, and a polishing pad is replaceably bonded to the upper surface of the sheet, so that the damage on the surface of the surface plate generated in, for example, replacement of the polishing pad or wafer polishing can be protected by the sheet.

Hereinafter, preferred embodiments of the present invention will be described with reference to FIG. 1 to FIG. 7. FIG. 1 is a perspective view showing an overview of a CMP apparatus 1 (wafer polishing apparatus). In this drawing, the CMP apparatus 1 is mainly composed of a surface plate 2 for polishing and a polishing head 3. The surface plate 2 is formed into a disk-like shape, and a rotating shaft 4 is coupled to the center of the lower surface thereof and rotated in the direction of an arrow A by driving a motor 5. A polishing pad 16 is attached to the upper surface of the surface plate 2. Herein, the polishing pad 16, which is generally commercially available, is referred to as the polishing pad 16 including a polishing cloth 6 and a double-sided adhesive tape 10 as shown in FIG. 3, which will be described later.

A wafer W pressed by a pressing means (not shown) is placed on the polishing pad 16 in the vicinity of the lower surface of the polishing head 3, and a rotating shaft 7 is coupled to the center of the upper surface of the polishing head 3 and driven by a motor (not shown) axially attached to the rotating shaft 7 so as to be rotated in the direction of an arrow B in FIG. 1. The rotating speeds of the surface plate 2 and the polishing head 3 are different from each other; and, even when both of them are rotated, no problem is caused in polishing of the wafer W. In addition, during polishing, an abrasive agent (slurry) is supplied onto the polishing pad 16 from a nozzle (not shown) Acidic slurry or alkaline slurry is employed as the slurry.

Next, an example of a specific constitution of the surface plate protecting device according to the present embodiment will be explained. In FIG. 2, a sheet 8 is bonded with the surface plate 2. Furthermore, the polishing pad 16 is bonded with the sheet 8. The wafer W is placed on the upper surface of the polishing pad 16 and pressed, and the wafer W is polished when the surface plate 2 and the polishing head 3 are rotated and the slurry is supplied.

The joint state of the polishing pad 16 and the sheet 8 is shown in detail in FIG. 3. In this drawing, the lower surface of the sheet 8 is bonded to the upper surface of the surface plate 2 by a strong adhesive agent 9. Herein, the adhesive agent 9 is shown as a single layer in FIG. 3; however, specifically, a double-sided adhesive tape similar to the double-sided adhesive tape 10 in the polishing pad 16 is used also in the lower surface portion of the sheet 8, and the adhesive agent of the double-sided portions of the double-sided adhesive tape is applied as the adhesive agent 9. The polishing pad 16 is bonded with the upper surface of the sheet 8 by an adhesive portion 10 a of the lower surface of the double-sided adhesive tape 10.

Thus, the strong adhesive agent 9 has adhesive force that is larger than the adhesive force of the adhesive portion 10 a of the double-sided adhesive tape 10 in the polishing pad 16; wherein the polishing pad 16 is formed that, when the polishing pad 16 is to be peeled off from the upper surface of the surface plate 2, merely the polishing pad 16 can be peeled off from the surface plate 2 while the sheet 8 is bonded to the surface plate 2.

Therefore, in regular replacement of the polishing pad 16, the polishing pad 16 can be readily peeled off from the upper surface of the sheet 8, and the polishing pad 16 can be readily replaced by bonding a new polishing pad 16 onto the upper surface of the sheet 8 by the part of the double-sided adhesive tape 10. Even when the pressing force of the polishing pad 16 is applied to the surface plate 2 in replacement of the polishing pad 16, the upper surface of the surface plate 2 is protected by the sheet 8, and the problem that, for example, damage, dent, or the like is generated on the upper surface of the surface plate 2 is solved.

Also, even when the wafer W projects out from the polishing head 3 and broken pieces thereof act to involve the polishing pad 16 and damage the upper surface of the surface plate 2, the upper surface of the surface plate 2 is reliably protected by the sheet 8, and generation of above described damage, etc. can be prevented. Therefore, polishing operation can be executed while the upper surface of the surface plate 2 always maintains a proper shape. Thus, the polishing operation is considerably effectively executed, high quality of the polished wafer W is maintained, and the replacement operation of the polishing pad 16 is readily and quickly executed. Therefore, the CMP apparatus 1 can be effectively and appropriately operated; and, as a result, the high-quality wafer W can be obtained, damage, etc. of the surface plate 2 can be suppressed as low as possible, and an economical advantage is also provided.

The sheet 8 employs a material that is excellent in chemical resistance property composed of, for example, a fluorine resin or polyethylene. In this case, it is not eroded by the slurry, which is composed of, for example, an acidic or alkaline material, the sheet 8 endures use of a long period, and, during that period, protection of the surface plate 2 as described above can be maintained.

In the case in which the fluorine resin or the like is employed as the material of the sheet 8, when the lower surface of the sheet 8 is subjected to surface treatment that increases the friction coefficient, even when an adhesive agent having adhesive force equal to the adhesive force of the adhesive portions 10 a and 10 b of the both-sided adhesive tape 10 in the polishing pad 16 is used as the adhesive agent that bonds the lower surface of the sheet 8with the upper surface of the surface plate 2, the adhesive force between the lower surface of the sheet 8 and the upper surface of the surface plate 2 can be reliably increased more than the adhesive force between the upper surface of the sheet 8 and the polishing pad 16. As a matter of course, in this case, when the strong adhesive agent 9 is used as the adhesive agent that bonds the lower surface of the sheet 8 with the upper surface of the surface plate 2, the adhesive force between the lower surface of the sheet 8 and the upper surface of the surface plate 2 can be further reliably increased.

As the surface treatment that increases the friction coefficient of the lower surface of the sheet 8, for example, treatment of reducing or removing the fluorine component of the lower surface of the sheet 8, which is made of the fluorine resin or the like, by chemical treatment or roughening treatment of the lower surface of the sheet 8 by mechanical blast treatment or the like is performed.

When the lower surface of the sheet 8 is subjected to the surface treatment that increases the friction coefficient, in regular replacement of the polishing pad 16, the polishing pad 16 can be independently, readily, and reliably peeled off from the sheet 8 bonded with the upper surface of the surface plate 2.

FIG. 4 shows another embodiment. In FIG. 4, both sides of the sheet 8 are coated in advance by adhesive agents 11 and 12 having different adhesive force. In this drawing, the lower surface side of the sheet 8 is coated by the adhesive agent 11 having large adhesive force, and the upper surface side thereof is coated by the adhesive agent 12 having small adhesive force. Herein, as well as the above described case, the adhesive agent of the both side portions of the double-sided adhesive tape is applied to the adhesive agents 11 and 12 coating the both sides of the sheet 8. It is also same in the case of FIG. 6, which will be described later, that the adhesive agent of the both side portions of the double-sided adhesive tape is applied to the adhesive agents coating the sheet 8.

In FIG. 4, the sheet 8 is bonded with the upper surface of the surface plate 2 by using the adhesive agent 11 of the lower surface side having large adhesive force, and the polishing cloth 6 is bonded by using the adhesive agent 12 of the upper surface side having small adhesive force. In this case, the bonding operation of the sheet 8 and the polishing cloth 6 is readily and quickly performed, and the workability of regular replacement of the polishing cloth 6 is also good.

FIG. 5 shows further another embodiment. In this drawing, in order to protect the adhesive agents 11 and 12 shown in FIG. 4, outer coating sheets 13 and 13 are bonded with the adhesive agents 11 and 12, respectively. Thus, the adhesive agents 11 and 12 are not damaged until the bonding operation is executed by using the respective adhesive agents 11 and 12, and the functions thereof are reliably protected. As a matter of course, when bonding is to be executed by using the adhesive agents 11 and 12, these outer coating sheets 13 and 13 are peeled off.

FIG. 6 shows an embodiment of the sheet 8 and the polishing pad 16. In this drawing, the surface of the sheet 8 to be bonded to the surface plate 2 side is coated with an adhesive agent 14 having adhesive force that is larger than the adhesive force of the adhesive portion 10 a of the double-sided adhesive tape 10 in the polishing pad 16 in advance. The surfaces of the adhesive agent 14 of the lower surface of the sheet 8 and the adhesive portion 10 a of the double-sided adhesive tape 10 in the polishing pad 16 may be joined with outer coating sheets in advance so as to protect the adhesive agent 14 and the adhesive portion 10 a as well as the embodiment of FIG. 5. As a matter of course, when respective bonding is to be executed by using the adhesive agent 14 and the adhesive portion 10 a of the double-sided adhesive tape 10, these outer coating sheets are naturally peeled off.

FIG. 7 is an explanatory drawing showing a replacement state of the sheet 8. In the embodiments of FIG. 3, FIG. 4, and FIG. 6, when the sheet 8 per se is damaged during polishing, the sheet 8 is peeled off from the upper surface of the surface plate 2, and a new sheet 8 is bonded with the upper surface of the surface plate 2 in the above described manner, thereby protecting the surface plate 2.

Note that, in the present invention, various modifications can be made without departing from the spirit of the present invention, and it goes without saying that the present invention pertains to the modifications. 

1. A surface plate protecting device in a CMP apparatus comprising a surface plate used in the CMP apparatus, wherein a sheet is bonded with an upper surface of the surface plate by an adhesive agent, a polishing pad is further replaceably bonded with the upper surface of the sheet, so that damage of the surface of the surface plate generated in replacement of the polishing pad, wafer polishing, or the like is protected by the sheet.
 2. The surface plate protecting device in the CMP apparatus according to claim 1, wherein the adhesive force of the adhesive agent bonding the upper surface of the surface plate with the sheet is larger than the adhesive force of the polishing pad.
 3. The surface plate protecting device in the CMP apparatus according to claim 1 or 2, wherein a chemically resistant material such as a fluorine resin is selected as the sheet.
 4. The surface plate protecting device in the CMP apparatus according to claim 1 or 3, wherein a lower surface of the sheet is subjected to surface treatment that increases a friction coefficient, and the adhesive agent bonding the lower surface of the sheet with the upper surface of the surface plate uses an adhesive agent having adhesive force equal to or more than the adhesive force of the polishing pad.
 5. A surface plate protecting device in a CMP apparatus comprising a surface plate used in the CMP apparatus, wherein a sheet protecting a surface of the surface plate is provided, both sides of the sheet are respectively coated by adhesive agents having different adhesive force, the adhesive agent of the lower surface side having the adhesive force larger than the adhesive force of the upper surface side, the lower surface of the sheet is bonded with the upper surface of the surface plate by the adhesive agent having the large adhesive force, and a polishing cloth is replaceably bonded with the upper surface of the sheet by the adhesive agent having the small adhesive force, so that damage of the surface of the surface plate generated in replacement of the polishing cloth, wafer polishing, or the like can be protected by the sheet.
 6. The surface plate protecting device in the CMP apparatus according to claim 1, 2, or 3, wherein the surface of the sheet in the surface plate side is coated in advance by an adhesive agent having adhesive force larger than the adhesive force of the polishing pad, the sheet is bonded with the upper surface of the surface plate, and the polishing pad is bonded with the upper surface of the sheet.
 7. The surface plate protecting device in the CMP apparatus according to claim 5 or 6, wherein an outer coating sheet for preventing adhesion with another material is bonded with the surface of the adhesive agent coating the sheet. 